Risk factors for a second nonsimultaneous hip fracture in a prospective cohort study.

INTRODUCTION: The risk factors for a second nonsimultaneous hip fracture are unclear, and in general, it is empirically assumed that they are similar to those associated with the first hip fracture. We aimed to determine the incidence of a second hip fracture and define the characteristics of the patients sustaining the event in a prospective cohort study in a Spanish population. MATERIALS AND METHODS: We conducted a multicentric, prospective cohort study in a representative sample of 45 hospitals from 15 autonomic regions in Spain. In total, the study included 994 patients. One hundred and one patients presented a nonsimultaneous contralateral hip fracture, constituting the intervention group. The remaining 893 patients presenting with a hip fracture formed the control group. The main outcome measures of this study were sociodemographic characteristics of the patient, comorbid conditions, and baseline and postfracture clinical outcomes (inpatient complications and acute mortality). RESULTS: The key fracture risk factors were a history of fragility fractures, the need for assistance when walking outdoors and a history of falls. There were no associations between the groups in any of the common fragility risk factors, including rheumatoid arthritis, secondary osteoporosis, or steroid consumption. The results showed that patients suffering a nonsimultaneous hip fracture had an increased risk of mortality after discharge compared with the control group. CONCLUSION: A nonsimultaneous second hip fracture leads to a near-significant increase in four-month mortality. In our study, this fracture was associated with a history of falls, prior fragility fractures, and the need for a walking aid.

Effectiveness of the Lapidus plate system in foot surgery: A PRISMA compliant systematic review.

Lapidus arthrodesis is an established standard procedure to correct various foot surgery problems and hallux limitus, hypermobility of the first ray, hallux abductus valgus, and symptomatic lesser metatarsal. After decades, many fixation methods in the orthopaedic surgery industry have been developed for decreasing complications and improving this technique. The aim of this PRISMA compliant systematic review is to analyse the effectiveness of several lapidus plate systems in foot surgery. We have carried out the first systematic review of the relevant published literature so as to systematically evaluate the scientific knowledge available now on this association, assigning predefined eligibility criteria. Fourteen studies were selected which had an overall of 738 cases. The first tarsal metatarsal joint and hallux valgus were treated by the application of different types of Lapidus plate system. The optimal level of the fixation in these procedures is related with the type and system insertion place of the plate with or without screw in each specific foot disease. There is an insufficient number of studies about the effectiveness of the different types of Lapidus plate system in foot surgery, and there is a need to increase outcomes knowledge on the level of the fixation, sort of the system, and insert place in foot surgery.

Effectiveness of calcaneal osteotomy in surgical treatment of foot conditions: A Prisma statement guidelines compliant systematic review.

Calcaneal osteotomy is a commonly established method used to correct various foot malalignment surgery problems that produce varus and valgus hindfoot abnormality as well as Haglund's deformity, cavovarus foot reconstruction, flatfoot deformity, plantar fasciitis, posterior tibial tendon insufficiency and planovalgus foot. After decades, several procedures in orthopaedic foot surgery have been suggested for reducing the risk of wound and neurovascular complications. The goal of this Prisma statement guidelines compliant systematic review was to establish the effectiveness and safety of calcaneal osteotomy in foot surgery. We have performed a novel systematic review of the current published literature in order to evaluate the scientific evidence now available on this association, assigning predefined exclusion and inclusion criteria. Eight investigations were selected which had 191 cases. The adult flatfoot, tibialis posterior reconstruction and cavovarus foot deformity were treated with different procedures of calcaneal osteotomy techniques. The adequate level of effectiveness of calcaneal osteotomy is associated with the kind and location of the incision, with or without screw application, in each specific foot condition. There is a limited number of scientific investigations of the effectiveness and safety of the different kinds of calcaneal osteotomy in foot surgery, and there is the need to enhance outcome knowledge on this foot surgery technique.

Survival analysis and influence of the surgical aggression of a cohort of orthopedic and trauma patients in a non-controlled spread COVID-19 scenario.

BACKGROUND: Determining the infection rate and mortality probability in healthy patients who have undergone orthopedic and trauma surgeries (OTS) during a period of uncontrolled COVID-19 transmission may help to inform preparations for future waves. This study performed a survival analysis in a cohort of non-infected OTS patients and determined the effect of COVID-19 on mortality. METHODS: This observational study included 184 patients who underwent OTS in the month before surgical activities ceased and before the implementation of special measures. Four groups of surgery (GS) were established based on the location of the surgery and the grade of inflammation produced. Crude risk of infection and infection rates were assessed. Survival and failure functions by GS were analyzed. Comparison of the Kaplan-Meier survival curves by GS was assessed. Cox regression and Fine-Gray models were used to determine the effect of different confounders on mortality. RESULTS: The crude risk of COVID-19 diagnosis was 14.13% (95% CI: 9.83-19.90%). The total incidence rate was 2.67 (1000 person-days, 95% CI: 1.74-3.91). At the end of follow-up, there was a 94.42% chance of surviving 76 days or more after OTS. The differences in K-M survivor curves by GS indicated that GS 4 presented a lower survival function (Mantel-Cox test, p = 0.024; Wilcoxon-Breslow test, p = 0.044; Tarone-Ware test, p = 0.032). One of the best models to determine the association with mortality was the age-adjusted model for GS, high blood pressure, and respiratory history, with a hazard ratio of 1.112 in Cox regression analysis (95% CI: 1.005-1.230) and a sub hazard ratio of 1.111 (95% CI: 1.046-1.177) in Fine-Gray regression analysis for competitive risk. CONCLUSIONS: The infection risk after OTS was similar to that of the general population in a community transmission area; the grade of surgical aggression did not influence this rate. The survival probability was extremely high if patients had not previously been infected. With higher grades of surgical aggression, the risk of mortality was higher in OTS patients. Adjusting for age and other confounders (e.g., GS, high blood pressure and respiratory history) was associated with higher mortality rates.

Analysis of biomechanical stresses caused by hindfoot joint arthrodesis in the treatment of adult acquired flatfoot deformity: A finite element study.

BACKGROUND: Treatments of adult acquired flatfoot deformity in early stages (I-IIa-IIb) are focused on strengthening tendons, in isolation or combined with osteotomies, but in stage III, rigidity of foot deformity requires more restrictive procedures such as hindfoot joint arthrodesis. Few experimental studies have assessed the biomechanical effects of these treatments, because of the difficulty of measuring these parameters in cadavers. Our objective was to quantify the biomechanical stress caused by both isolated hindfoot arthrodesis and triple arthrodesis on the main tissues that support the plantar arch. METHODS: An innovative finite element model was used to evaluate some flatfoot scenarios treated with isolated hindfoot arthrodesis and triple arthrodesis. RESULTS AND CONCLUSIONS: When arthrodeses are done in situ, talonavicular seems a good option, possible superior to subtalar and at least equivalent to triple. Calcaneocuboid arthrodesis reduces significantly both fascia plantar and spring ligament stresses but concentrates higher stresses around the fused joint.

Infection Due to Saksenaea vasiformis Following a Spider Bite.

Cutaneous mucormycosis due to Saksenaea vasiformis species is exceptional. There have been about 40 reported cases worldwide, with most being fatal. We report an exceptional nonlethal case of mucormycosis due to S. vasiformis following a spider bite. The patient was in an immunosuppressed state owing to previous chemotherapy and diabetes mellitus. The origin of the inoculation was the bite of a Loxosceles laeta spider, which caused loxoscelism. The initial skin injury was quickly progressive, requiring amputation of the right upper limb. After surgical intervention and suitable antifungal treatment, the patient was discharged with resolution of accompanying pulmonary disease. Infections due to S. vasiformis are probably underdiagnosed. To avoid fatal outcomes, a high index of clinical suspicion in patients with quickly progressive necrotic lesions of soft tissues and systemic dissemination is important.

Arthroscopic Volar Capsuloligamentous Reattachment and Reinforcement to Bone.

Background: Injuries of the volar ligaments of the wrist are not uncommon, but their arthroscopic treatment presents a significant challenge. The objective of this paper is to introduce a technique for reattaching (in acute injuries) or reinforcing (in chronic injuries) various volar wrist ligaments to the bone, using standard wrist arthroscopic dorsal and volar portals. Methods: There are three common steps for all the arthroscopic volar capsuloligamentous reattachments or reinforcements Step 1 - Volar Portal Establishment: volar radial, volar ulnar and volar central portals are used depending on which structure needs to be reattached or reinforced. Step 2 - Anchor Placement: the anchor is positioned at the site where the ligament has been detached. Step 3 - Capsuloligamentous Suture and Knotting: a knot pusher is introduced inside the joint from the dorsal portal and advanced inside the volar portal where the threads of the anchor are located. The knot pusher is loaded with the threads and retrieved to the dorsal portal. A 16G Abbocath, loaded with a loop is used to pierce the volar ligaments. The loop of the Abbocath is captured from the dorsal portal and loaded with the threads. Both threads are taken to the volar portal and knotted after releasing the traction. This way the knot is placed out of the wrist and the ligaments are reattached or reinforced to the bone. Result: This technique has been used to reinforce and reattach the scapholunate and lunotriquetral ligaments and to reattach the radiocarpal ligaments and the Poirier space. Since this procedure has been performed in various conditions and in conjunction with other ligament treatments (such as perilunate injuries, carpal bone fractures, distal radius fractures, and reinforcement or reattachment of the dorsal portions of intrinsic ligaments), specific results are not presented. Conclusions: The described technique enables the reattachment and reinforcement of most volar ligaments to the bone using standard wrist arthroscopic portals. It can be performed in conjunction with the treatment of the dorsal portion of intrinsic ligaments or other wrist injuries.

Predictive model for a second hip fracture occurrence using natural language processing and machine learning on electronic health records.

Hip fractures (HFx) are associated with a higher morbidity and mortality rates, leading to a significant reduction in life quality and in limitation of patient´s mobility. The present study aimed to obtain real-world evidence on the clinical characteristics of patients with an initial and a second hip fracture (HFx) and develop a predictive model for second HFx using artificial intelligence. Electronic health records from one hospital centre in Spain from January 2011 to December 2019 were analysed using EHRead® technology, based on natural language processing and machine learning. A total of 1,960 patients with HFx were finally included during the study period after meeting all inclusion and exclusion criteria. From this total, 1835 (93.6%) patients were included in the HFx subgroup, while 124 (6.4%) were admitted to the second HFx (2HFx) subgroup. The mean age of the participants was 84 years and 75.5% were female. Most of comorbidities were more frequently identified in the HFx group, including hypertension (72.0% vs. 67.2%), cognitive impairment (33.0% vs. 31.2%), diabetes mellitus (28.7% vs. 24.8%), heart failure (27.6% vs. 22.4%) and chronic kidney disease (26.9% vs. 16.0%). Based on clinical criteria, 26 features were selected as potential prediction factors. From there, 16 demographics and clinical characteristics such as comorbidities, medications, measures of disabilities for ambulation and type of refracture were selected for development of a competitive risk model. Specifically, those predictors with different associated risk ratios, sorted from higher to lower risk relevance were visual deficit, malnutrition, walking assistance, hypothyroidism, female sex, osteoporosis treatment, pertrochanteric fracture, dementia, age at index, osteoporosis, renal failure, stroke, COPD, heart disease, anaemia, and asthma. This model showed good performance (dependent AUC: 0.69; apparent performance: 0.75) and could help the identification of patients with higher risk of developing a second HFx, allowing preventive measures. This study expands the current available information of HFx patients in Spain and identifies factors that exhibit potential in predicting a second HFx among older patients.

Arthroscopic ligamentoplasty of the dorsal and volar portions of the scapholunate ligament.

Classical arthroscopic techniques for scapholunate instability consist of debridement, thermal shrinkage, and percutaneous pinning. Good results are obtained in acute lesions or in chronic partial tears, but they are less predictable when the lesion is complete, because of the poor healing capacity of the scapholunate ligament and because it is not possible to perform an anatomic ligamentous reconstruction with these techniques. Open techniques are thus required for reconstruction, but they damage the soft tissues. We recently published a description and cadaver study of an arthroscopic ligamentoplasty, trying to combine the advantages of arthroscopic techniques (minimally invasive surgery) and open techniques (reconstruction of the ligament). With this approach, it is possible to reconstruct the dorsal scapholunate ligament and the secondary stabilizers while causing minimal damage to the soft tissues and avoiding injury to the posterior interosseous nerve and detachment of the dorsal intercarpal ligament. The current report describes an additional step to this technique with which it is possible to reconstruct the volar portion of the scapholunate ligament. We also describe an early mobilization postoperative protocol that we believe is equally important.

Sequential management of postmenopausal health and osteoporosis: An update.

Increased life expectancy means that women are now in a hypoestrogenic state for approximately one-third of their lives. Overall health and specifically bone health during this period evolves in accordance with aging and successive exposure to various risk factors. In this review, we provide a summary of the approaches to the sequential management of osteoporosis within an integrative model of care to offer physicians a useful tool to facilitate therapeutic decision-making. Current evidence suggests that pharmacologic agents should be selected based on the risk of fractures, which does not always correlate with age. Due to their effect on bone turnover and on other hormone-regulated phenomena, such as hot flushes or breast cancer risk, we position hormone therapy and selective estrogen receptor modulators as an early postmenopause intervention for the management of postmenopausal osteoporosis. When the use of these agents is not possible, compelling evidence supports antiresorptive agents as first-line treatment of postmenopausal osteoporosis in many clinical scenarios, with digestive conditions, kidney function, readiness for compliance, or patient preferences playing a role in choosing between bisphosphonates or denosumab during this period. For patients at high risk of osteoporotic fracture, the "anabolic first" approach reduces that risk. The effect on bone health with these bone-forming agents or with denosumab should be consolidated with the subsequent use of antiresorptive agents. Regardless of the strategy, follow-up and treatment should be maintained indefinitely to help prevent fractures.

Low-dose prophylaxis protocol for heterotopic ossification after hip preservation surgery in a sport participants cohort.

BACKGROUND: Heterotopic ossification (HO) is a well-known complication of arthroscopic and open surgical treatment of femoroacetabular impingement (FAI). Incidence of heterotopic ossification has been reported in the literature between 0% and 44% after hip arthroscopy and between 18.2% and 25% after anterior mini-open surgery. Currently, pharmacological prophylaxis with NSAIDs and selective COX-2 inhibitors are commonly used and their effectiveness is well documented in literature. HYPOTHESIS: We hypothesized that the low-dose prophylaxis protocol with selective cox-2 inhibitors decreases the risk of heterotopic ossification in open or arthroscopic hip preservation surgery in athletes. METHODS: This study is an analysis of prospectively gathered data on 98 sport participant patients who underwent arthroscopic or anterior mini-open treatment for FAI between April 2008 and April 2018. All the patients received postoperative oral prophylaxis with 60 mg etoricoxib once daily for two weeks. Post-operative X-rays were performed at 1, 3, and 12 months after surgery and reviewed by two orthopedic surgeons blinded to the type and side of surgery. HO were graded according to the Brooker classification. Descriptive statistics was used to analyze demographic data. Bivariate analysis was performed to analyze the association of HO with each of the following variables: type of surgery, physical activity, time of evolution of symptoms, age at surgery, and sex. Finally, a regression model analysis was performed to determine the presence of confounding effects between variables. RESULTS: The study cohort was composed of 54 patients in the arthroscopic treatment group and 44 patients in the anterior mini-open group. HO was identified in 6 (13.6%) patients in the mini-open group. No HO was identified in the arthroscopic group. In the bivariate analysis, "type of surgery" was the only variable that showed a statistically significant association with HO (p = 0.007). CONCLUSION: Results of this study suggest that anterior mini-open treatment was characterized by a higher risk of HO development compared to hip arthroscopy for femoroacetabular impingement treatment regardless of pharmacological prophylaxis. The treatment regimen of 60 mg etoricoxib daily for two weeks was an effective prophylaxis for HO formation in sport participant patients compared with data available in the literature.

Computer-Assisted Surgery Enables Beginner Surgeons, Under Expert Guidance, to Achieve Long-Term Clinical Results not Inferior to Those of a Skilled Surgeon in Knee Arthroplasty.

Purpose: The purpose of this study is to determine whether the use of a surgical navigation system in total knee replacement (TKR) enables beginner and intermediate surgeons to achieve clinical PROM outcomes as good as those conducted by expert surgeons in the long term. Methods: We enrolled 100 consecutive patients whose total navigated knee arthroplasty (TKA) was performed in our institution from 2008 to 2010. According to the principal surgeon's surgical experience, the patients were divided into three groups: (1) beginner surgeons, with no more than 30 previous knee replacement performances, (2) intermediate surgeons, with more than 30 but not more than 300, and (3) expert surgeons, with more than 300 knee replacements. Demographic data collected on the cohort included gender, laterality, age, and body mass index (BMI). The outcome measures assessed were Forgotten Joint Score (FJS), implant positioning, limb alignment, and prosthesis survival rate. A margin of equivalence of ± 18.5 points in the FJS scale was prespecified in terms of the minimal clinically important difference (MCID) to compare the FJS results obtained in the long period between the groups of interest. Results: The mean follow-up was 11.10 ± 0.78, 10.86 ± 0.66, and 11.30 ± 0.74 years, respectively, for each of the groups. The long-term FJS mean score was 80.86 ± 21.88, 81.36 ± 23.87, and 90.48 ± 14.65 for each group. The statistical analysis proved noninferiority and equivalence in terms of the FJS results reported in the long term by patients in Groups 1 or 2 compared to those in Group 3. More specifically, it has been proved that the mean difference between groups is within the interval of equivalence defined in terms of the MCID. The overall prostheses survival rate was 93.7%. Conclusion: Navigated assisted TKA, under expert guidance, can be as effective when performed by beginner or intermediate surgeons as performed by senior surgeons regarding the accuracy of implant positioning, limb alignment, and long-term clinical outcome.

Numerical modelling of cancellous bone damage using an orthotropic failure criterion and tissue elastic properties as a function of the mineral content and microporosity.

BACKGROUND AND OBJECTIVE: Elastic and strength properties of lamellar tissue are essential to analyze the mechanical behaviour of bone at the meso- or macro-scale. Although many efforts have been made to model the architecture of cancellous bone, in general, isotropic elastic constants are assumed for tissue modelling, neglecting its non-isotropic behaviour. Therefore, isotropic damage laws are often used to estimate the bone failure. The main goals of this work are: (1) to present a new model for the estimation of the elastic properties of lamellar tissue which includes the bone mineral density (BMD) and the microporosity, (2) to address the numerical modelling of cancellous bone damage using an orthotropic failure criterion and a discrete damage mechanics analysis, including the novel approach for the tissue elastic properties aforementioned. METHODS: Numerical homogenization has been used to estimate the elastic properties of lamellar bone considering BMD and microporosity. Microcomputed Tomography (µ-CT) scans have been performed to obtain the micro-finite element (µ-FE) model of cancellous bone from a vertebra of swine. In this model, lamellar tissue is orientated by considering a unidirectional layer pattern being the mineralized collagen fibrils aligned with the most representative geometrical feature of the trabeculae network. We have considered the Hashin's failure criterion and the Material Property Degradation (MPDG) method for simulating the onset and evolution of bone damage. RESULTS: The terms of the stiffness matrix for lamellar tissue are derived as functions of the BMD and microporosity at tissue scale. Results obtained for the apparent yield strain values agree with experimental values found in the literature. The influence of the damage parameters on the bone mechanics behaviour is also presented. CONCLUSIONS: Stiffness matrix of lamellar tissue depends on both BMD and microporosity. The new approach presented in this work enables to analyze the influence of the BMD and porosity on the mechanical response of bone. Lamellar tissue orientation has to be considered in the mechanical analysis of the cancellous bone. An orthotropic failure criterion can be used to analyze the bone failure onset instead of isotropic criteria. The elastic property degradation method is an efficient procedure to analyze the failure propagation in a 3D numerical model.

Mechanical Alignment in Knee Replacement Homogenizes Postoperative Coronal Hip-Knee-Ankle Angle in Varus Knees: A Navigation-Based Study.

After knee replacement, postoperative lower limb alignment is influenced by the geometry of the prosthesis position and surrounding soft tissue that contributes to the hip-knee-ankle (HKA) angle. The purpose of this study is to determine the dynamic coronal HKA angle after mechanical alignment in total knee replacement using computer navigation. We conducted a pre-post design study of 71 patients with varus osteoarthritic knees on which total knee arthroplasty was performed. The HKA was measured before and at the end of the surgical procedure with the patient in the supine position using a navigation system at 30, 60, and 90 degrees of knee flexion. Postoperative implant position and flexion and extension gaps were assessed. HKA was clustered in three preoperative dynamic patterns (PDPs; Varus-Neutral, Varus-Valgus, and Varus-Varus). There were statistically significant differences in the dynamic coronal HKA between the preoperative and postoperative statuses after mechanically aligned knee replacement (with p < 0.0001) Before the surgical procedure, statistically significant differences were found between patterns at any angle of flexion confirming a well-differentiated preoperative dynamic behavior between the three groups. Postoperatively, 98.6% (71 out of 72) of the knees were within ± 3 degrees of the HKA at full extension. Fifty-eight knees (80.6%) were assessed to a "within-range" postoperative dynamic alignment at any grade of flexion considered. There are differences between the preoperative and postoperative status of the dynamic coronal HKA angle after mechanically aligned knee replacement. We proposed that an excellent dynamic HKA alignment is achieved not only at full extension within the range of 0 ± 3 degrees but also when this alignment is maintained at 30, 60, and 90 degrees.

Outcomes after terrible triads of the elbow treated with the current surgical protocols. A review.

Dislocation of the elbow associated with radial head and coronoid fracture, the so-called "terrible triad" of the elbow, is challenging to treat and has a history of complicated outcomes. However, advances in the knowledge of elbow kinematics combined with improved implants and surgical techniques during the past few years have led to the development of standard surgical protocols. This review article analyses the results in 137 elbow triad injuries of five studies treated using the current protocols. These include fixation of the coronoid fracture, repair or replacement the radial head, and repair of the lateral ligament complex, reserving medial collateral ligament repair and application of hinged external fixation for patients with residual instability. Treatment of these demanding injuries appeared effective in the majority of cases, i.e. with an average of 31 months of follow-up, overall flexion arc was 111.4°, averaged flexion was 132.5° with forearm rotation of 135.5°, Mayo elbow performance score was 85.6 points, and Broberg-Morrey score was 85 points. Nevertheless, the patient should be informed about the incidence of complications including joint stiffness, ulnar nerve symptoms or post-traumatic arthritis.

Peroneus Longus overload caused by soft tissue deficiencies associated with early adult acquired flatfoot: A finite element analysis.

BACKGROUND: Peroneus Longus tendinopathy has been related to overload from cavus and ankle instability. The etiology of isolated Peroneus Longus tendon synovitis has not been elucidated. Loss of foot arch integrity as a cause of isolated Peroneus Longus overload is difficult to establish using cadaver modeling. Our objective was to analyze Peroneus Longus stress changes in pathological scenarios related to flatfoot development. METHODS: A three-dimensional finite element foot model which included the foot bones and main soft tissues that maintain the arch was used. Simulations were performed in midstance of gait. Tendon's maximum principal stress and von Mises were calculated in scenarios where the plantar fascia, spring ligament and the posterior tibial tendon were weakened. FINDINGS: Decreasing plantar fascia stiffness thus weakening arch integrity increases Peroneus Longus stresses by over three times. Additional failure of tissues that support arch, such as the spring ligament and tibialis posterior tendon further overloads this tendon. The absence of Peroneus Longus also affects stresses in tissues that maintain the arch. Stress concentrations increase in the plantar component of the Peroneus Longus. INTERPRETATION: Results offer an explanation into isolated Peroneus Longus overload synovitis. Recognition of failing medial arch structures that occur in early acquired flatfoot as a cause of Peroneus Longus overload could help in its treatment. We caution the practice of transfer of peroneus brevis to longus in surgical treatment of flatfoot as it may further overload an overloaded tendon and focus should be on restoration of arch stability to offload stresses within it.

Modified full-face snorkel masks as reusable personal protective equipment for hospital personnel.

Here we adapt and evaluate a full-face snorkel mask for use as personal protective equipment (PPE) for health care workers, who lack appropriate alternatives during the COVID-19 crisis in the spring of 2020. The design (referred to as Pneumask) consists of a custom snorkel-specific adapter that couples the snorkel-port of the mask to a rated filter (either a medical-grade ventilator inline filter or an industrial filter). This design has been tested for the sealing capability of the mask, filter performance, CO2 buildup and clinical usability. These tests found the Pneumask capable of forming a seal that exceeds the standards required for half-face respirators or N95 respirators. Filter testing indicates a range of options with varying performance depending on the quality of filter selected, but with typical filter performance exceeding or comparable to the N95 standard. CO2 buildup was found to be roughly equivalent to levels found in half-face elastomeric respirators in literature. Clinical usability tests indicate sufficient visibility and, while speaking is somewhat muffled, this can be addressed via amplification (Bluetooth voice relay to cell phone speakers through an app) in noisy environments. We present guidance on the assembly, usage (donning and doffing) and decontamination protocols. The benefit of the Pneumask as PPE is that it is reusable for longer periods than typical disposable N95 respirators, as the snorkel mask can withstand rigorous decontamination protocols (that are standard to regular elastomeric respirators). With the dire worldwide shortage of PPE for medical personnel, our conclusions on the performance and efficacy of Pneumask as an N95-alternative technology are cautiously optimistic.

Arthroscopic Trapeziectomy and Suture Button Suspensionplasty: A Review of the Literature and Description of the "Three-Step Arthroscopic Trapeziectomy Technique".

In the last two decades, surgeons have rapidly developed arthroscopic techniques to treat basal joint osteoarthritis. Such techniques spare the joint capsule and ligaments, allow more accurate staging of cartilage degeneration to determine the most appropriate treatment, and decrease the risk of injury to the radial artery and superficial branch of the radial nerve. Arthroscopic resection arthroplasty of the trapezium can be performed as either partial or complete trapeziectomy. Many papers have described partial trapeziectomy but few have discussed complete trapeziectomy. Suture button implants avoid the drawbacks of temporary fixation using Kirschner wire, as well as the drawbacks of ligament reconstruction, which necessitates the sacrifice of a tendon and involves both wide exposure and scar tissue. This paper aimed to review the published data on the arthroscopic treatment of basal thumb osteoarthritis, with a special focus on stabilization using suture button suspensionplasty, and to present a technique that structures this procedure into three steps, allowing it to be performed in an easier, more organized, and faster way.

Finite element analysis of secondary effect of midfoot fusions on the spring ligament in the management of adult acquired flatfoot.

BACKGROUND: Surgical treatment of adult acquired flatfoot deformity can involve arthrodesis of the midfoot to stabilize the medial column. Few experimental studies have assessed the biomechanical effects of these fusions, because of the difficulty of measuring these parameters in cadavers. Our objective was to quantify the biomechanical stress caused by various types of midfoot arthrodesis on the Spring ligament. To date this is not known. METHODS: An innovative finite element model was used to evaluate flatfoot scenarios treated with various combinations of midfoot arthrodesis. All the bones, cartilages and tissues related to adult acquired flatfoot deformity were included, respecting their biomechanical characteristics. The stress changes on the Spring ligament were quantified. Both foot arch lengthening and falling were measured for each of the midfoot arthrodeses evaluated. FINDINGS: Arthrodesis performed for stabilization of the talonavicular joint leads to a higher decrease in stress on the Spring ligament. Talonavicular fusion generated a Spring ligament stress decrease of about 61% with respect to the reference case (without any fusion). However, fusing the naviculocuneiform joints leads to an increase in the stress on the Spring ligament. INTERPRETATION: This important finding has been unknown to date. We advocate caution regarding fusion of the naviculocuneiform joint as it leads to increased stresses across the Spring ligament and therefore accelerates the development of planovalgus.